With the rapid development in computer technologies, more and more enterprises collect, store, manipulate, and organize every kind of information/data in computers. Since business opportunities, research topics, etc. may be hidden in these huge amount of data/information, some enterprises sell their data for money. It is possible that a user buys data (called “released data”) from an enterprise and then distributes copies of the data to other users, which means that other users derive these data for free. Currently, there is no technique for tracing a released data in the data market. Even a manager of an enterprise has the doubt that some data may be originated form his/her company, there is no way to prove that.
Consequently, there is an urgent need for a mechanism that can trace released data without harming the precision of the data severely.